Method and system for compensating for external impedance of an energy carrying component when controlling an electrosurgical generator

• US 20060224152A1
• Filed: 03/27/2006
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Sherwood Services AG
• Inventors: Behnke, Robert, Wham, Robert H.
• Granted Patent: US 9,474,564 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/0072 Current
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00767 Voltage
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00827 Current
• CPC Class Codes: A61B 2018/00869 Phase
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00892 Voltage

Abstract

A control system for use with an electrosurgical generator which delivers electrosurgical energy to tissue has a control module. The module includes a processor executing an algorithm. The algorithm has the steps of determining a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator and determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator. The algorithm has the steps of determining phase information corresponding to a phase shift between the voltage signal and the current signal and determining a characteristic related to the electrosurgical energy delivered to the tissue using the phase information, the sensed voltage value and the sensed current value.

Claims

1. A control system for use with an electrosurgical generator that delivers electrosurgical energy to tissue, the control system comprising:

a control module including at least one processor, said at least one processor executing an algorithm comprising the steps of;

determining a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator;

determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator;

determining phase information corresponding to a phase shift between the at least one voltage signal and at least one current signal; and

determining a characteristic related to the electrosurgical energy delivered to the tissue using the phase information, the sensed voltage and the sensed current.

2. The control system according to claim 1, wherein the algorithm further comprises the step of:

sampling impedance information corresponding to impedance of an energy carrying component; and

wherein the determining at least one characteristic step further comprises;

using the sampled impedance information, and modulating the electrosurgical energy delivered to the tissue using the sampled impedance information.

3. The control system according to claim 1, wherein the phase information is obtained from circuitry selected from the group consisting of zero cross phase detector circuitry, processing circuitry and any combinations thereof.

4. The control system according to claim 3, wherein the processing circuitry executes an algorithm selected from the group consisting of a single-band Fourier transform algorithm, a multi-band Fourier transform algorithm, an FFT algorithm, a Goertzel algorithm, an equivalent to a Fourier transform algorithm and any combinations thereof.

5. The control system according to claim 2, wherein the sampled impedance information relates to at least one parameter selected from the group consisting of an inductance of the energy-carrying component, a resistance of the energy-carrying component, a capacitance of the energy-carrying component, a leakage capacitance of the energy-carrying component and any combinations thereof.

6. The control system according to claim 2, wherein the sampled impedance information is obtained by a device, the device selected from the group consisting of a user input device, an encoded readable information associated with the at least one energy-carrying component, a mechanical device setting associated with the at least one energy-carrying component, a stored information accessible to the at least one processor and any combinations thereof.

7. The control system according to claim 1, wherein the at least one characteristic of the electrosurgical energy delivered to the patient is selected from the group consisting of voltage, current, impedance and power.

8. The control system according to claim 7, wherein the algorithm further comprises the step of controlling at least one of voltage, current and power output by the electrosurgical generator in accordance with the determined at least one characteristic related to the delivered electrosurgical energy.

9. A control system for use with an electrosurgical generator that delivers electrosurgical energy to tissue, the control system comprising:

a control module including at least one processor, said at least one processor executing an algorithm comprising the steps of;

determining a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator;

determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator;

determining impedance information corresponding to impedance of at least one energy-carrying component; and

determining a characteristic related to the electrosurgical energy delivered to the patient using the impedance information, the sensed voltage and the sensed current.

10. The control system according to claim 9, wherein the impedance information relates to at least one of inductance, resistance, capacitance, leakage capacitance of the at least one energy-carrying component and any combination thereof.

11. The control system according to claim 9, wherein the impedance information is obtained via at least one of a user input device, an encoded information associated with the at least one energy-carrying component, a mechanical device setting associated with the at least one energy-carrying component, a stored information accessible to the at least one processor, and any combinations thereof.

12. The control system according to claim 9, wherein the at least one characteristic of the electrosurgical energy delivered to the patient is selected from the group consisting of voltage, current, impedance and power.

13. The control system according to claim 12, wherein the algorithm further comprises the step of controlling at least one of voltage, current and power output by the electrosurgical generator in accordance with the determined characteristic related to the delivered electrosurgical energy.

14. An electrosurgical generator comprising:

a control system including;

a control module including at least one processor, said at least one processor executing an algorithm comprising the steps of;

determining at least one of a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator;

determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator;

determining a phase shift value corresponding to a phase shift between the voltage and current signals;

determining a characteristic related to the electrosurgical energy delivered to the patient using the phase shift value, the sensed voltage and the sensed current; and

modulating the electrosurgical energy based in part on the characteristic.

15. The electrosurgical generator according to claim 14, wherein the algorithm further comprises the step of determining impedance information corresponding to impedance of at least one energy-carrying component;

and

using the impedance information in the determining step to determine at least one of voltage, current and power.

16. The electrosurgical generator according to claim 14, wherein the phase shift value is obtained from circuitry selected from the group consisting of zero cross phase detector circuitry, processing circuitry and any combinations thereof.

17. The electrosurgical generator according to claim 14, wherein the processing circuitry executes an algorithm selected from a single-band Fourier transform algorithm, a multi-band Fourier transform algorithm, an Fast Fourier transform algorithm, a Goertzel algorithm, and a combination thereof.

18. The electrosurgical generator according to claim 14, wherein the algorithm further comprises the step of determining at least one of voltage, current and power output by the electrosurgical generator in accordance with the determined characteristic related to the delivered electrosurgical energy.

19. A method for regulating electrosurgical energy output by an electrosurgical generator, the method comprising the steps of:

determining a sensed voltage value corresponding to a sensed voltage signal output by the electrosurgical generator;

determining a sensed current value corresponding to a sensed current signal output by the electrosurgical generator;

determining a phase shift value corresponding to a phase shift between the voltage signal and a current signal;

determining a characteristic related to the electrosurgical energy delivered to the tissue using the phase shift value, the sensed voltage value and the sensed current value; and

determining at least one of voltage, current and power output by the electrosurgical generator in accordance with the determined characteristic related to the delivered electrosurgical energy.

20. The method according to claim 19, further comprising the step of

determining impedance information corresponding to impedance of at least one energy-carrying component;

and

using at least the impedance information to determine of at least one of voltage, current and power output.

21. A method for compensating an output of an electrosurgical system for an external device of an electrosurgical system comprising the steps of:

determining an impedance factor of the external device utilizing a first algorithm;

determining a voltage factor adjacent an electrode utilizing a second algorithm;

determining a current factor adjacent said electrode utilizing a third algorithm;

determining a phase parameter factor of the output utilizing a fourth algorithm;

determining at least one of the power, current, and voltage lost in the external device using at least one of the impedance factor, the voltage factor, the current factor, and the phase parameter factor to obtain a difference value;

comparing the difference value to a threshold value related to the external device; and

modulating at least one of the power, the load, and the current, the modulation of the at least one of the power, the load, and the current being dependent on the relationship of the difference value to the threshold value.

22. The method of claim 21, wherein the step of calculating the phase parameter factor of the output includes the step of calculating a phase differential of a voltage signal and a current signal of the output.

23. The method of claim 22, wherein the step of calculating the phase parameter factor of the output includes the step of calculating a plurality of phase differentials between successive voltage signals and current signals of the output.

24. An electrosurgical system comprising:

an electrosurgical generator configured to deliver energy;

an electrosurgical treatment tool adapted to connect to the generator, said electrosurgical treatment tool including at least one electrode, and an impedance sensor;

a current sensor configured to measure the output current delivered by the generator, said electrosurgical generator including;

a microprocessor electrically connected to the current sensor and the impedance sensor that calculates one or more parameters of an electrosurgical energy;

said electrode of said treatment tool including a conduit defined therein for transmitting electrosurgical energy therethrough, said conduit including;

an encoded rating capable of being communicated to an input of the electrosurgical generator, said encoded rating relating to a loss of energy from the conduit; and

wherein the electrosurgical generator outputs a compensated signal attributable to the energy loss from the conduit.

25. The apparatus of claim 24, wherein said encoded rating is automatically or visually communicated to the generator.